题干

(8分)某学生欲用已知物质的量浓度的盐酸来测定未知物质的量浓度的NaOH溶液,选择甲基橙作指示剂.请填写下列空白:
(1)用标准的盐酸滴定待测的NaOH溶液时,左手握酸式滴定管的活塞,右手摇动锥形瓶,眼睛注视_____________,滴定终点的判断方法是________________________
(2)下列操作中可能使所测NaOH溶液的浓度数值偏低的是          

A:酸式滴定管未用标准盐酸润洗就直接注入标准盐酸

B:滴定前盛放NaOH溶液的锥形瓶用蒸馏水洗净后没有干燥

C:酸式滴定管在滴定前有气泡,滴定后气泡消失

D:读取盐酸体积时,开始仰视读数,滴定结束时俯视读数

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D

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